Growth and Heavy Metal Accumulation of
作者: 会同衫木林站 更新时间: 2015-09-28
Recent studies report that exposure to manganese (Mn) results in neurotoxicity and/or Parkinson’s disease (PD) in welders  and nurses . This phenomenon has aroused widespread concern on a global scope [3–5]. Manganese-induced clinical neurotoxicity is associated with a motor dysfunction syndrome commonly referred to as manganism , which is related with significantly higher reactive oxygen species (ROS) generation . It is therefore great concern about the environmental risk posed by manganese waste mines because most of the tailings have been left without any management and have become the main source of heavy metal contamination of agricultural soils and crops in the mining areas . Soil heavy metal pollution poses high carcinogenic and non-carcinogenic risks to the public, especially to children and those living in the vicinity of heavily polluted mining areas [9,10]. Multiple pathways of health risk due to heavy metal exposure in China were reviewed by Zhuang et al. , with risks coming from the intake of home-grown rice and vegetables. The use of polluted groundwater and
pond water also poses potential risk to human health , for instance, the high manganese concentration (1.21 ppm; U.S. Environmental Protection Agency reference, <0.05 ppm) in water used by local residents had caused a markedly below-average performance in tests of memory  due to human nervous system damage cuased by excessive intake of manganese . Chai et al.  found that arsenic and manganese were the largest contributors to human health risks for the local people drinking groundwater in the Xiangjiang watershed. The neurotoxicologic effects of water manganese in children  due to their significantly higher Mn concentrations in blood (9.5 μg/L) and hair (12.6 μg/L) was observed . Furthermore, water Mn concentrations of 0.66 μg/L  (i.e., higher than the WHO guideline of <0.4 μg/L) may lead to higher infant mortality .